Dermatome

ABSTRACT

In a dermatome for preparing skin grafts, skin is placed on the exterior convex surface of a support which forms part of a hollow cylinder. An elongated hollow shaft extends along the axis of the cylinder and is fixed to end walls of the support while an operating shaft extends through and beyond the hollow shaft. The operating shaft terminates in eccentric portions which have a common axis parallel and spaced from the axis of the operating shaft. A pair of arms is carried by these eccentric portions and they are capable of being adjustably fixed thereto. These arms carry distant from the operating shaft a reciprocating blade which can reciprocate parallel to the operating shaft while swinging with the arms and the operating shaft about the axis of the curved wall on which the skin is supported. The hollow shaft is itself supported on a pair of forks in upwardly directed notches thereof.

United States Patent Inventors Ledislnv Barinka;

Frantlsek Libra, Brno, Czechoslovakia App]. No. 839,880 Filed July 8, 1969 Patented Feb. 16, 1971 Assignee Chepos Zavody chemickeho a Potravinarskeho Strojlrenstoi Brno, oborovy podnik Brno, Czechoslovakia DERMATOME 8 Clelmu, 4 Drawing Figs.

LS. 83/4, 83/647, 83/662, 83/9155, 128/305 Int. 826d 4/42, A6lb 17/32 Fleld ofSearch......... 83/4, 527, 648, 662, 915.5, 647; 128/305.5, 305

References Cited UNITED STATES PATENTS orl AQQMEQQQLLt: 1:22;-

Primary Examiner-James M. Meister' A1!orney- Richard Low ABSTRACT: In a dermatome for preparing skin grafts, skin is placed on the exterior convex surface of a support which forms part of a hollow cylinder. An elongated hollow shaft extends along the axis of the cylinder and is fixed to end walls of the support while an operating shaft extends through and beyond the hollow shaft. The operating shaft terminates in eccentric portions which have a common axis parallel and spaced from the axis of the operating; shaft. A pair of arms is carried by these eccentric portions and they are capable of being adjustably fixed thereto. These arms carry distant from the operating shaft a reciprocating blade which can reciprocate parallel to the operating shaft while swinging with the arms and the operating shaft about the axis of the curved wall on which the skin is supported. The hollow shaft is itself supported on a pair of forks in upwardly directed notches thereof.

DERMATOME BACKGROUND OF THE INVENTION The present invention relates to dermatomes.

At the present time when skin grafts are required for any substantial area, it is necessary to perform live or six distinct skin-grafting operations. The skin grafts are generally prepared on a hollow drum which is of the shape of half of a cylinder. A blade is adjusted so as to cut away the subcutaneous tissue to leave the skin in a condition where it may be prepared for grafting operations.

With relatively small-sized structures of this latter type there is a disadvantage in that during the operation adjacent cement which is even located on untreated skin is affected. It therefore becomes necessary to remove the applied cement and to reapply it in a uniform layer. In almost all cases during the first cutting operation with the small-sized apparatus, the volume of blood in thetissue is pressed out onto the adjacent area so as to reduce the capability of the skin to adhere to the supporting surface. Furthermore, the conventional small-sized apparatus leaves uneven margins, and uneven thickness is encountered in the prepared skin. As a result, extreme complications are encountered in the adaptation of the margins of the individual skin portions to each other and to the adjoining skin so that operations of undesirably long periods of time are encountered. Even under the most careful operating conditions best results cannot be achieved.

SUMMARY OF THE INVENTION It is accordingly a primary object of the invention to provide an apparatus which will avoid the above-referred-to drawbacks.

More particularly, it is an object of the invention to provide an apparatus which can be conveniently and quickly manipulated in such a way as to reliably achieve skin grafts of very large size, which heretofore could not be efficiently prepared, so that in this way the number of grafts required for any given operation can be very greatly reduced. A large series of advantages are achieved with respect'to the short time of the operation, the improved appearance of the skin on the healing thereof, and the great reliability in the operation.

In addition, it is an object of the present invention to provide a construction of this type which is simple and rugged, which can be very easily adjusted, and which can be manufactured and sold at relatively low cost.

Further, it is an object of the invention to provide a structure which lends itself to easy dismantling so that various components can readily be removed for sterilizing purposes.

Thus, it is an object of the invention to provide a construction which is readily portable and canat the same time be easily sterilized, being broken down into separate components for this purpose.

Still further, it is an object of the invention to provide a construction of this type which can be readily adjusted so as to accommodate itself to the particular requirements of a particular operator and thus to provide the most comfortable and easiest operating conditions for anygiven operator.

According to the invention, the apparatus includes an elongated curved wall forming part of a cylinder and having an exterior convex surface to support the skin during the preparation thereof. This support has a pair of end walls which are releasably connected with an elongated hollow support shaft. The axis of this latter shaft is coincident with the axis of the cylinder of which the curved wall forms a part. The ends of this hollow shaft are removably supported in upwardly directed notches of a pair of supporting forks which themselves are removably received in upper hollow tubes of a suitable stand. 7

An elongated operating shaft extends through the hollow shaft beyond the latter and terminates in a pair of elongated eccentric end portions on which a pair of arms is supported for swinging movement, these arms terminating distant from the operating shaft in a blade carrier which supports a blade for reciprocating motion. A fixing means is provided for releasably fixing the cylindrical skin support on the supporting forks at a preselected angular position which is most preferred by the operator. A lever is connected to the operating shaft for giving to the latter a preselected angular position, and the arms which carry the blade support are themselves capable of being longitudinally adjusted so as to adjust the distance of the blade with respect to the skin support; In addition. the arms are swingable on the eccentrics to have a very precise adjustment of the blade, and once this adjustment is made. screws, which form a further adjusting meansreleasably fix the arms to the operating shaft at the required! angular position. Then, the blade may be swung with the operating shaft about the axis of the cylinder while the blade is reciprocated back and forth to remove subcutaneous tissue and thus leave the skin in a condition for the additional treatments required in connection with the skin grafting operations.

BRIEF DESCRIPTION OF DRAWINGS l DESCRIPTION OF PREFERRED EMBODIMENTS The dermatome of the invention, as; shown in the drawings, includes a supporting stand 1 (FIG. I). This supporting stand terminates in a pair of parallel, upwardly directed hollow tubes having open top ends for receiving a pair of fork supports 2. These fork supports include downwardly extending elongated portions which are received in the upper regions of the tubes of the support 1. The pair of fork supports have upwardly directed plates formed with upwardly directed notches having open top ends at the top edge of these plates. An elongated hollow connecting tube 3 extends between and is fixed to the fork supports 2. The. tube 3 is itself formed midway between its ends with a transverse bore through which an elongated rod 4 freely passes.

The upwardly directed notches of the pair of fork supports 2 receive the ends of an elongated hollow shaft 5 for free rotary movement on the pair of supports 2. Within the opposed ends of the hollow shaft 5 are situated a pair of bearing sleeves 7. An intermediate portion 6 of the shaft 5 is made somewhat thicker than the remainder of the shaft and has an exterior knurled surface so that the portion 6 can serve as a handle, for purposes described below.

An elongated operating shaft- 8 extends coaxially through the hollow shaft 5 and is supported for rotary movement by the bearings 7 mounted in the opposed ends of the hollow shaft 5. The operating shaft 8 has elongated opposed ends extending through substantial distances; beyond the opposed ends of the hollow shaft 5.

A pair of rings or flanges 9 are permanently fixed, as by welding, to the opposed ends of the hollow shaft 5. The axis of the shaft 5 not only coincides withthe axis of the shaft 8. but also with the axis of a cylinder along which the wall II extends, this wall having an exterior surface formed with slight arcuate grooves for supporting a skin section during preparation thereof for skin-grafting operations, in a well known manner. The curved elongated wall 11 is fixed with a pair of end walls 10, and a releasable connecting means connects these end walls 10 to the rings 9. This connecting means takes the form of screws passing through openings of end walls 10 and threaded into threaded bores which are formed in the rings 9. Thus, the skin-support I1 is fixed with the hollow shaft- The elongated operating shaft 8 terminates at its opposed ends in elongated end portions which have a common axis parallel to and spaced from the axis of the shaft 8 so that these end portions are eccentric. A pair of elongated telescopic carrying arms 13 are provided for carrying a cutting blade 15 in a manner described in greater detail below. The arms 13 terminate in end portions which are turnable on the eccentric end portions of the shaft 8. An adjusting means is capable of fixing the arms, 13 at preselected angular positions on the eccentrics, and includes the rotary screw members 19 which have threaded shanks threaded into threaded bores formed in the eccentrics so that these screws can fix the arms 13 on the eccentrics at preselected angular positions. I

The arms 13 have portions 13a which telescopically receive elongated portions 13b (FIG. 3). The portions 13b are threaded to adjusting screws 20 so that through these screws it is possible to adjust the length of the arms 13.

At their outer ends which are distant from the shaft 8 the arms 13 are fixed to an elongated member 14a which is formed with a dovetail groove receiving the dovetail rib of a member 14b (FIG. 4). These members form a holder 14 for a blade 15. The part 14b can be reciprocated with respect to the part 140 in order to reciprocate the blade 15 longitudinally.

A lever 16 is fixed to and projects from the shaft 8 for adjusting the angular position of the latter.

The blade 15 of the dermatome is situated in a suitable slot of the holder 14, and set screws 17 are provided, as shown in FIG. 1, for releasably fixing the blade 15 in position. The blade, when not in use, may be protected by a suitably grooved elongated cover member 18.

The means for fixing the support with the shaft 5 at a given angular position includes plates 21 swingable on screw members threaded into the plates of the fork supports 2. These clamping plates 21 have ends which overlap the rings 9. Thus, through the fixing screw members it is possible to clamp the plates 21 to the fork supports so as to clamp the rings 9 thereto. The clamp plates 21 are directly swingable on fixing screws 22 which may be tightened and loosened in order to connect and release the rings 9 from the fork supports 2. An elongated handle 23 may extend from each of the clamping plates to facilitate the angular movement thereof.

A pair of angular manually engageable handles 24 are respectively fixed to the reciprocating part 14b of the holder 14 so that through these handles 24 it is possible for the operator to reciprocate the blade back and forth.

The above described structure operates as follows:

The clamping plates 2] are used to fix the rings 9, the entire support 10, 11, and the hollow shaft-5 at a predetermined angular position which will locate the support 10, 11 at the most comfortable and convenient attitude for the operator. The support 11 is thus fixed against turning in the selected posi tion. Then the blade 15 is fixed by way of the screws 17 in the slot of the holder 14. At this time the elongated rod 4 extends through the transverse opening of the tube 3 to a location beneath the holder 14 so as to support the latter at a convenient elevation for attachment of the blade 15. The blade is covered by the cover 18.

In order to set the apparatus up for operation the operator will remove the cover 18 and will turn the screws so as to locate the blade 15 directly next to the surface of the support 11. The pair of screws 20 are also capable of being independently adjusted for maintaining the blade 15 precisely parallel to the axis of the wall 11. Then the screws 19 of the angular adjusting means are loosened and the pair of arms 13 are turned as a unit with the holder 14 and the blade 15 around the axis of the pair of eccentric portions of the shaft 8. This will result in movement of the blade 15 to a very precisely determined extent away from the surface of the skin support 11 so that the thickness of the cut skin will be very accurately regulated. Prior to this operation, the lever 16 is manipulated for first locating the shaft 8 at a preselected angular position, so that in this way the angular positions of the pair of eccentrics are initially adjusted. With the distance between the support 11 and the blade 15 thus precisely adjusted, the screws 19 are tightened to fix the arms 13 on the eccentrics.

Now the dermatome is set up and the skin-cutting operations can proceed. The skin which is to be grafted is glued in a known manner to the exterior surface of the drum 11. Then the cutting away of the subcutaneous tissue takes place. The operator will grasp the handles 24, and while swinging the arms 13 and the blade 15 around the axis of the shaft 8, will simultaneously reciprocate the blade 15 back and forth. lf required, the clamping plates 21 can be loosened and the drum l1 swung to another position before the operations are completed to maintain the cutting always at a convenient location for the operator. The clamps 21 will be loosened and again tightened by way of the screws 22.

As soon as the subcutaneous tissue has been cut away in this manner, the skin which adhered to thesupport 11 is removed therefrom. Then further treatments are made in preparation for the skin-grafting operations, all of which is well known.

With the operations thus completed at the dermatome of the invention, all of the mechanical parts are loosened. The blade 15 is removed from the holder 14. The operator will loosen the clamps 21, and the entire drum 11 with the shaft 5 will be swung away from the operator so as to render the handle 6 easy to grasp. Now the entire shaft 5 together with the drum 11 can simply be removed from the fork supports so that this unit can be readily transported and sterilized. The forkshaped supports themselves can be removed, inasmuch as they are interconnected by the tube 3 and can simply be raised out of the hollow vertical tubes of the stand 1. The fork supports 2 and the shaft 3 can also be sterilized.

After completion of the sterilizing operations, all of the component parts are again assembled and the apparatus is ready for further use.

With the dermatome of the invention, it becomes possible to provide large one-piece skin grafts for tissue reserves as well as for immediate treatments, if required. Also, with our dermatome, it is possible not only to have an easy assembly and disassembly, east transportability and sterilization, but in addition the most precise control of the thickness ofthe skin;

We claim:

1. In a dermatome, a hollow support having a curved, elongated wall forming part of a cylinder and having an exterior convex surface for supporting skin during preparation of the latter for skin grafting operations, said support having a pair of end walls respectively situated at ends of said curved elongated wall thereof, an elongated hollow shaft having an axis coinciding with that of the cylinder of which said curved elongated wall forms a part, connecting means connecting said end walls to said hollow shaft, an elongated rotary operating shaft extending through said hollow shaft and beyond the latter, said rotary operating shaft terminating in identical eccentric portions which have a common. axis parallel to and spaced from the common axis of said hollow and operating shafts, a pair of carrying forks respectively having notches which are open at their upper ends and respectively carrying said hollow shaft at the region of said end walls, fixing means releasedly fixing said hollow shaft and said support therewith to said forks at a selected angular position, a pair of elongated parallel arms extending perpendicularly from said operating shaft and formed with openings which respectively receive said eccentric portions, elongated blade-support means extending between and carried by said arms distant from said operating shaft and extending substantially parallel to the latter, said blade-support means coacting with a cutting blade to support the latter for reciprocation back and forth parallel to the common axis of said shafts, first adjusting means coacting with said pair of arms for adjusting the length thereof, and second adjusting means coacting with said arms for fixing the latter at predetermined angular position with respect to said eccentric portions of said operating shaft to locate the blade at a given distance from the exterior convex surface of said support, so that with the latter distance set it is possible to rotate said operating shaft about its axis to displace said blade, while it reciprocates longitudinally, around the axis of said elongated wall to remove subcutaneous tissue from a skin section mounted on said support in preparation for skin grafting operations.

2. The combination of claim 1 and wherein a stand is provided with a pair of upwardly directed tubes for receiving said forks for carrying the latter at a preselected elevation 3. The combination of claim 1 and wherein an elongated shaft means extends between and connects said fork supports to each other, said fixing means including rotary fixing members fixed by screws releasedly to said forks and overlapping part of said connecting means which connects said end walls to said hollow shaft.

4. The combination of claim 3 and wherein said connecting means includes flanges situated at the ends of said hollow shaft and projecting therefrom and screws passing through said end walls into said flanges.

5. The combination of claim 3 and wherein said shaft means carries a rod which extends perpendicularly to the common axis of said hollow and operating shafts to a location beneath said blade-support means so as to support the latter at a preselected elevation.

6. The combination of claim 1 and wherein said hollow shaft carries at its ends bearings through which said operating shaft extends.

7. The combination of claim 1 and wherein said second adjusting means includes rotary threaded members threaded into said eccentric portions of said operating; shaft for fixing said arms thereto.

8. The combination of claim 7 and wherein a lever is fixed to said operating shaft for turning the latter to a preselected angular position before said arms are fixed by said second adjusting means. 

1. In a dermatome, a hollow support having a curved, elongated wall forming part of a cylinder and having an exterior convex surface for supporting skin during preparation of the latter for skin grafting operations, said support having a pair of end walls respectively situated at ends of said curved elongated wall thereof, an elongated hollow shaft having an axis coinciding with that of the cylinder of which said curved elongated wall forms a part, connecting means connecting said end walls to said hollow shaft, an elongated rotary operating shaft extending through said hollow shaft and beyond the latter, said rotary operating shaft terminating in identical eccentric portions which have a common axis parallel to and spaced from the common axis of said hollow and operating shafts, a pair of carrying forks respectively having notches which are open at their upper ends and respectively carrying said hollow shaft at the region of said end walls, fixing means releasedly fixing said hollow shaft and said support therewith to said forks at a selected angular position, a pair of elongated parallel arms extending perpendicularly from said operating shaft and formed with openings which respectively receive said eccentric portions, elongated blade-support means extending between and carried by said arms distant from said operating shaft and extending substantially parallel to the latter, said blade-support means coacting with a cutting blade to support the latter for reciprocation back and forth parallel to the common axis of said shafts, first adjusting means coacting with said pair of arms for adjusting the length thereof, and second adjusting means coacting with said arms for fixing the latter at predetermined angular position with respect to said eccentric portions of said operating shaft to locate the blade at a given distance from the exterior convex surface of said support, so that with the latter distance set it is possible to rotate said operating shaft about its axis to displace said blade, while it reciprocates longitudinally, around the axis of said elongated wall to remove subcutaneous tissue from a skin section mounted on said support in preparation for skin grafting operations.
 2. The combination of claim 1 and wherein a stand is provided with a pair of upwardly directed tubes for receiving said forks for carrying the latter at a preselected elevation.
 3. The combination of claim 1 and wherein an elongated shaft means extends between and connects said fork supports to each other, said fixing means including rotary fixing members fixed by screws releasedly to said forks and overlapping part of said connecting means which connects said end walls to said hollow shaft.
 4. The combination of claim 3 and wherein said connecting means includes flanges situated at the ends of said hollow shaft and projecting therefrom and screws passing through said end walls into said flanges.
 5. The combination of claim 3 and wherein said shaft means carries a rod which extends perpendicularly to the common axis of said hollow and operating shafts to a location beneath said blade-support means so as to support the latter at a preselected elevation.
 6. The combination of claim 1 and wherein said hollow shaft carries at its ends bearings through which said operating shaft extends.
 7. The combination of claim 1 and wherein said second adjusting means includes rotary threaded members threaded into said eccentric portions of said operating shaft for fixing said arms thereto.
 8. The combination of claim 7 and wherein a lever is fixed to said operating shaft for turning the latter to a preselected angular position before said arms are fixed by said second adjusting means. 